1. Field of the Invention
The invention relates to a method for the processing of medical image data so as to determine output function data, situated at grid points of a selected grid, from input function data situated at grid points of a Cartesian grid, as well as to a device in which the method can be carried out.
2. Description of Related Art
A method of this kind is required for many medical applications in which medical image data is processed. For example, for 2D/3D recording it is important to have an efficient method for calculating two-dimensional projections from a three-dimensional data set. Nowadays, for this purpose use is made of, for example a ray tracing algorithm in which the integral of grey values within a pre-operative 3D data set is calculated along a ray from the radiation source to an image point in the detector plane (in the case of X-ray imaging). In order to enable intra-operative use of such a method, the calculation must be performed sufficiently quickly since a plurality of projections of the pre-operative data set must be calculated at different angles and be compared with currently measured projections so as to enable a 2D/3D recording to be made. A method of the kind set forth is used not only for X-ray imaging, but also for other medical imaging techniques, for example for magnetic resonance tomography and X-ray computer tomography (CT), notably for the calculation of projections.